In early 1496, a Venetian sea cap-tain named Giovanni Caboto ap-peared in the English port of Bristol, carrying no money but a warrant from King Henry VII to obtain a ship and sail on a voyage of trade and dis-covery.

England would call him John Cabot, and from 1496 to 1498 he set sail three times for the New World. On the second voyage he made land-fall in what is now Newfoundland and claimed North America for England and the Roman Catholic Church.

That much is known. But of his third voyage there is nothing. He apparently vanished .

Alwyn Ruddock, a historian at the University of London who had researched Cabot for more than half her life, several times promised a book, but never wrote it. Instead, before she died in 2005 at 89, she or-dered her executor to destroy her research. Seventy-eight bags of papers were incinerated, leaving scholars astounded.

Now an important piece of the Ruddock riddle has been solved. In 2010, an international team of schol-ars found a set of 514-year-old Italian ledgers that Dr. Ruddock had found decades earlier but which had dis-appeared. They showed that in the spring of 1496, Cabot got money from the London branch of a Florentine banking house called the Bardi.

The explorer was long thought to have been financed by merchants in Bristol. But the new findings demon-strate that he was staked at least in part by the same Italian financiers who helped his illustrious contempo-raries like Amerigo Vespucci, Vasco da Gama, Bartolomeu Dias and, of course, Christopher Columbus.

The ledgers also provide convinc-ing proof for Dr. Ruddock’s claim that she found about 25 Cabot documents never before seen by modern schol-ars. “She wasn’t making anything up,” said Evan T. Jones, a maritime historian at the University of Bristol.

Nearly seven years ago, after Dr. Ruddock’s death, Dr. Jones found the book proposal she had submitted to the University of Exeter Press. In it, she outlined an incredible tale.

Dr. Ruddock had found that Cabot was closely connected with Lon-don’s influential Italian émigré community. But her most tantaliz-ing assertions concerned the third voyage, in 1498. She claimed Cabot had not disappeared but left Bristol with five ships carrying Italian fri-ars intent on establishing a mission in the North Atlantic lands he had visited the previous year.

The friars disembarked on the Newfoundland coast, to build the first Christian settlement in North America. Then, Cabot sailed south along the North American coast, claiming everything he saw for the British Crown. According to Dr. Rud-dock, he was the first European to see what is today the United States.

Cabot finally reached the coast of South America, where he ran into one of Columbus’s captains, probably Alonso de Ojeda, who warned him off. Cabot turned back and reached New-foundland in early 1500, Dr. Ruddock said, then returned to Bristol, where he died four months later.

While all of this is plausible, much of it is not yet documented. But, in 2010, a colleague told Dr. Jones that he had made a lucky find on Amazon: Dr. Ruddock’s personal copy of the seminal work on Cabot, James A. Williamson’s “The Cabot Voyages and Bristol Discovery Un-der Henry VII,” published in 1962.

Dr. Jones traced the seller, Lisa Shanley, who had bought Dr. Rud-dock’s modest house in Hampshire and was selling off the contents of its library. She was aware of the Rud-dock story and invited Dr. Jones and his colleague Margaret Condon for a visit.

Dr. Ruddock’s study was still in-tact — including a cupboard she had used , the labels still affixed to its pigeonholes. One of them read “The Bardi firm, of London.”

“We knew from Ruddock’s notes that an Italian banker had support-ed the voyage, but didn’t know which one,” Dr. Jones said. Now they did. The company’s records were found in the archives of the Guicciardini, another prominent Florentine fam-ily. When the relevant ledger was opened, there was the confirming entry:

“John Cabot, of Venice, on 27 April [1496], is debited for 10 pounds ster-ling, paid in cash ... so that he could go and find the new land.”